SPID#: 31 Lumbar spinal fusion is commonly performed in humans but the failure rate of bone union is reported to range from 5-36%. Recently, both osteoinductive growth factors synthesized by recombinant DNA technology and bovine derived bone protein (BP) have been shown to induce bone formation in heterotopic sites Recombinant human Brain Morphogenetic Protein (rhBMP-2) and BP have both been effective in generating spine fusions in a rabbit model. To determine the appropriate dose of these growth factors for human use and to determine the speed of healing, a non-human primate model has been chosen. Higher doses than expected were required to make bone in the primate, but both treatments were successful. Studies in the upcoming year will focus on the precise doses and explore alternative carrier materials that will better bind the growth factors. These studies are critical to providing the information needed for the next step which is human clinical trials. This treatment, if successful, will signifcantly impact on the care of spine patients and prevent multiple surgeries in the 5-35% of patients who do not heal their spine fusions on the first attempt.